Writing to a register when the status is UVM_NOT_OK

[tudor.timi]

In UVM_REG, what is the intended behavior when a write to a register triggers a bus error? I would expect that the mirrored value is not updated as long as I signal the bus error inside the bus2reg method of my reg_adapter. Here is a slightly modified excerpt from the user guide.

virtual function void bus2reg(uvm_sequence_item bus_item, ref uvm_reg_bus_op rw);
  apb_rw apb;
  if (!$cast(apb,bus_item)) begin
    `uvm_fatal("NOT_APB_TYPE", "Provided bus_item is not of the correct type")
    return;
  end
  rw.kind = apb.kind ? UVM_READ : UVM_WRITE;
  rw.addr = apb.addr;
  rw.data = apb.data;
  rw.status = apb.error ? UVM_NOT_OK : UVM_IS_OK;
endfunction

I see that even in cases when the APB bus signals an error and I set the status in the rw as UVM_NOT_OK, the mirrored and the desired values of my registers get updated. Am I interpreting this UVM_NOT_OK thing wrong?

[balaji c]

Hi Tudor,

 

the same problem i am also facing.

 

i just want to check if status is UVM_NOT OK, then RAL model is updating or not.

 

then i hardcoded the status in bus2reg wantedly and i used explicit predictor method (FRONT DOOR),

 

when i read status register from DUT then in seq, i am getting read data as 0. but at the same time when i did "get" for the status register in RAL, then my value is already updated.

 

how to control ral updation when status is UVM_NOT_OK. ?
 

[tudor.timi]

What I ended up doing was creating my own subclass of uvm_reg_predictor that handles UVM_NOT_OK. I don't have access to the code right now, but it should be pretty easy for you to do by just having a quick look at that class.

[shawn]

On 2/16/2015 at 8:32 AM, tudor.timi said:

What I ended up doing was creating my own subclass of uvm_reg_predictor that handles UVM_NOT_OK. I don't have access to the code right now, but it should be pretty easy for you to do by just having a quick look at that class.

Updating predictor sounds a good idea . Did you keep the adapter code as you mentioned or changed it back to standard 

Quote

     rw.Data = apb_trans.Data;
       rw.status = UVM_IS_OK;

  end else begin  
       rw.status = UVM_NOT_OK;